Planned Release Date: Jun 4, 2026

About This Demo

You failed math class. Math didn't forget.

Zero Sum is a pencil on paper style twin-stick shooter. Your enemies are numbers and your weapon is math. No health bars. No hit points. Just raw arithmetic violence.

A "48" is charging at you. You fire ÷2. Now it's "24". Three more divisions: "12," "6," "3." Now switch to minus. Bang. Bang. Bang. Zero. Gone. Next.

That was the easy part.

Your Arsenal Is Unconventional

Forget guns. You carry operators. Minus and Plus are your reliable sidearms. Precise but boring, until they save your life. Division rips through enemies. Root turns big numbers into rubble. Modulo is a powerful grenade that can nuke even the biggest numbers if played right.

Multiplication? A slow trap. An AoE effect that slows everything it touches. Useful if you're smart enough to set up a kill with it. And then there's Sigma, a vortex grenade that sucks in every nearby enemy and combines them into a single number whose value is the sum of everything it ate. Turn a massive swarm of numbers into one big, easy-to-handle target.

Every operator changes the battlefield. Every shot requires a decision. Every clean kill and clever combo rewards bonus points. Integer split, perfect root, modulo blast. The game knows when you're showing off and rewards you for it.

The Numbers Fight Back

Enemies aren't just walking health bars. A prime number can't be cleanly divided. A factorial grows exponentially if you ignore it. Rethink to deal with Negatives. You can't outrun fast enemies. You don't just shoot, you solve.

Bosses That Would Make Mathematicians Sweat

Each boss is built around a mathematical concept that wants you dead (3 out of 9 bosses await you in the demo):

The Sigma Snake

• a colossal snake composed of numerical segments. To defeat a segment, you must deplete its value to exactly zero; fail to do so and the segment breaks away to hunt you down, adding their remaining values to its head. Once the body is gone, the head detaches and pursues you with a power level equal to the accumulated sum of every mistake you made.

The Factorial Factory

• an inconspicuous boss that launches factorial projectiles. 9! splits mid-air into 9 × 8 × 7 × 6 × …, each number racing toward its anchor to recombine into something enormous. Kill the pieces before they merge or face their giant product.

The Prime Sieve Spider 

• an eight-legged boss whose web is the Sieve of Eratosthenes. Trapped in its grid, you must identify and destroy the composites and avoid the prime traps. Hit the wrong number and it breaks free as a real enemy. Clear the web to expose a leg joint. Fail, and the entire web turns into a swarm.

Sketched by Hand, Animated Like a Fever Dream

Zero Sum looks like your notebook came alive and got angry. Enemies are the doodles you drew when you were bored in math class. Except these doodles want revenge.